<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <style>
        html {
            width: 100%;
            height: 100%;
        }

        body {
            width: 100%;
            height: 100%;
        }

        img.normal {
            height: auto;
        }

        img.big {
            width: 50%;
            height: 50%;
        }

        img.small {
            width: 10%;
            height: 10%;
        }
    </style>
</head>

<body>

    <img class="normal" src="肖申克的救赎.jpg" width="311" height="463" /><br>
    <img class="big" src="肖申克的救赎.jpg" width="311" height="463" /><br>
    <img class="small" src="肖申克的救赎.jpg" width="311" height="463" />

</body>

</html>